Layout table and coordinate reader



Jan. 19, 1965 Filed Feb. 8. 1961 R. c. BENTON 3,165,834

LAYOUT TABLE AND COORDINATE READER 5 Sheets-Sheet 1 28 f n 40 HINVENTOR. Robert 6. Benton M, Mam

HIS A TTORNE Y5 Jan 19, 1965 R. c. BENTON LAYOUT TABLE AND COORDINATEREADER 5 Sheets-Sheet 2 Filed Feb. 8, 1961 INVENTOR. Robert 62 BentonHIS ATTORNE Y3 Jan. 19, 1965 R. c. BENTON LAYOUT TABLE AND COORDINATEREADER 5 Sheets-Sheet 3 Filed- Feb. 8. 1961 H 0 LHI I IIIIIIIAMUIIIIIIIIHi5 ATTORNEYS mm mm. VB 8 a n... m. M F R Y 2 2 8 w 2 m 05L 0 .i U m 1 oa W n 2 6 0 N Jan. 19, 1 965 R. c. BENTON 3,165,834

LAYOUT TABLE AND COORDINATE} READER Filed Feb. 8, 1961 5 Sheets-Sheet 4INVENTOR.

Fig-II M flaw HIS ATTORNEYS Jan. 19, 1965 R. c. BENTON LAYOUT TABLE ANDCOORDINATE READER 5 Sheets-Sheet 5 Filed Feb. 8. 1961 INVENTOR. Robe f6. Benton .llllll. llllll & HIS ATTORNEYS United States Patent I)3,165,834 LAYOUT TABLE AND CQQRDINATE READER Robert C. Benton, StateCollege, Pa, assignor to Centre Circuits, Inc., State College, Pa., acorporation of Pennsylvania Filed Feb. 8, 1961, Ser. No. 87,859 12Claims. (Cl. 33-1) The present invention relates to a device serving asa combined layout table and coordinate reader. This device is mountedfor universal rectilinear movement along two coordinate axes and whensuperimposed above any point within its scope of travel, it can be usedto fix the coordinates of that point to a given number of decimal placesfairly rapidly and with high accuracy.

One difiiculty characteristic of practice in the past is keeping thetransverse bridge member of a layout table precisely at right angles tothe parallel longitud nal ways which are disposed one at each end of thebridge. In moving, one end of the bridge exhibits a tendency to lead theopposite end and thusplace the bridge in a somewhat diagonal positionbetween the ways rather than keeping square at all times in itspositions.

Because of this difiiculty, it is the practice to resort in some casesto parallel lead screw arrangements on the Ways or in other cases to usepressure guides on one longitudinal way only, seeking to insuresquareness of the bridge with respect to that Way. In either event,careful machining of the table parts is essential and the precisionnecessary and constant attention to maintenance of the table inserviceleads to considerable expense.

The present invention, through use of a principle of providing opposingrows of accurately adjustable locator pins on the ways and throughresort to regular micrometer gage structure for accuracy, overcomes theforegoing ditficulties, and in a practical economical way as will now beexplained. Certain features, objects and advantages are either coveredherein or will become apparent when, for a better understanding of theinvention, reference is made to the following description taken inconjunction with the accompanying drawings in which:

FIGURE 1 is a plan view of a table embodying the present invention; 7

FIGURE 2 is an elevational View in transverse section taken along thesection lines IIII of FIGURE 1;

FIGURE 3 is a fragmentary plan view corresponding to FIGURE 1 butshowing the micrometer carriage to entaken in section along the linesVIII--VIII of FIGURE 7;

FIGURE 9 is a fragmentary plan View of an enlarged portion of FIGURE 1;

FIGURE 10 is a transverse sectional view in elevation taken along thelines X-X of FIGURE 9;-

FIGURE 11 is a plan view in section of a detail of FIGURE 10 taken alongthe section lines XI-XI thereof;

FIGURE 12 is a plan view in section of a detail taken along the sectionlines XIIXII of FIGURE 10; and

FIGURES l3 and 14 are views in longitudinal section taken along therespective section lines XIIL-XIII and XIVXIV of FIGURE 12.

More particularly, in FIGURES l and 2 of the drawings, a micrometercarriage 20 is mounted to a traversing inch away from a Zero pin 69 Islide 72.

bridge 22 according to this invention both for movement with the bridgein the Y direction toward and from the bridges zero position shown bythe dotted lines 22a and for separate movement in the X directionindependently 'of the bridge, toward and from the zero position of thecarriage shown by the dotted lines 20a. The carriage '20 is thus capableof universal rectilinear movement with respect to a table base plate 24,and, for the ultimate purpose of this movement, it carries an instrumentholder and 2 and a companion longitudinally extending right Y way 3%.The bridge ZZ'has end trucks 32 and34 carrying pluralities of sets ofrollers including the rollers 36 and the roller 38 for rolling along thelongitudinal ways 28 and 3b. The set of rollers 36 and the roller 38form a three-point suspension for the sake of stability.

' A series of gusset plates 40 rigidifies the position of and directlysupports the left way 2;; on the table base plate 24. The right way 3%has a base plate adjustment bar 44 i at one end connecting it to thebase plate 24, whereas another series of gusset plates 42 and a baseplate adjustlocatorpins 48 which are adjusted so as to be consecutivemultiples of one inch away from the zero reference pin 48b. The trucks32 and 34 are lockable to these pins 48 so that if, for example, theyengage the twelfth locator pin vaway from the zero pin 48 the trucks 32and 34 will accurately lock the bridge 22 in its twelve-inch position ofadvancement. The locking and unlocking is controlled by ahandle-operated cam shaft 50 carried by the bridge 22 and operable torotate a transversely extending crank shaft 52 which actually controlsthe locking. Thecanr shaft 5b is rotated from either end by means oftwistable I handles 54 and 56 fast thereto.

An insert 58 in the bridge 22 carries another line 0 locator pins 6!}which are consecutive multiples of one Locking and unlocking of themicrometer carriage 20 with respect to the pins 60 is accomplished by acam and cam shaft structure ;62 which is rotated by means of ahand-twisted handle 45.

handle 64. These pins 48 and 60 thus constitute accurate gages of eachposition of the carriage 20.

The carriage 20 supports gages consisting of a longitudinally disposedmicrometer 68 and a transversely disposed micrometer 70 for positioningslides in a manner controlling the positionv of the instrument holder 26as will now be explained.

- -More particularly, in FIGURES 3 and 4, the instrument holderifi'formspart of a longitudinally movable Sets of ball bearings 74 disposed oneset on each side of the slide 72 support that longitudinalslide withrespect to the upper spaced-apart ways 76 carried by a transverse slide78. The longitudinal position of the slide 72 is controlled by a pair ofreturn springs 80 .72 and instrument holder 26 are mounted for universalrectilinear movement with respect to the micrometer carriage 20. I

The longitudinally movable slide 72 carries an upstanding pivot bracketpost 88 to which a counterweight arm 90 is pivoted at 92 for a purposeas will now be ex lained.

More particularly, in FIGURES and 6, a pivot bracket for thecounterweight arm 90 is formed of a pivot bracket post 88 and a flatbracket attachment base 94 secured to the slide 72. An instrument 96which is secured in the holder 26 is also secured to the counterweightarm 90 at its longer end. On the short end of the arm 90 which is at theopposite side of the pivot 92, a weight 98 is carried which counters theweight of the instrument 96. In this manner, the weight of theinstrument is efiectively transferred to a noneccentric position thuskeeping the micrometer carriage in static balance.

If the device is to be employed as a coordinate reader, the instrument96 consists of an optical reading head providing the propermagnification and having concentric rings .in the reticle for accuratelylocating centers. If the device is to be employed as a layout table, the

instrument 96 consists of a suitably mounted scribe or punch by means ofwhich a blank may be properly marked at center points each correct toprecise coordinates.

The understructure of the bridge 22 comprises a full length, downwardlyopen channel 100 carrying a mechanism box 1112 providing connections,not shown, whereby rotation of the cam shaft 50 rotates the transverselyextending crank shaft 52 for unlocking the bridge trucks (not shown)from the ways at opposite ends of the bridge 22.

The micrometer gages 68 and 70 of FIGURES 5 and 6, respectively, areaxially adjustable as indicated from their dotted-line, fully retractedpositions and are connected to the respective longitudinal slide 72 andthe transverse slide 78 by the same general type of connection. In eachcase, e.g., the micrometer 70, a precision thrust bearing 104 (FIGURE 6)carries a shoe 106 by which the micrometer is connected'in slack-freeengagement to the appropriate slide (78). The slides are therefore-movable to decimal readings of three place or four place accuracy asdesired, up to a full'one inch length of stroke foreach micrometer.

In the carriage 20, a downwardly open channel forms the base 108 of thecarriage and rides on X ways provided by short, upstanding flanges onthe bridge 22. This channel-shaped carriage base 108 includes a set ofhorizontally disposed bridge engaging rollers 110 (FIGURES 5 and 6)providing for vertical alignment and further includes a truck 112carrying a set of vertically disposed rollers 114 providing for rollingmovement in X direction along the bridge 22.

The locator pins 60 carried by the insert 58 have an eccentric upperportion provided with a tool slot or similar means 116 whereby they canbe rotatably adjusted to assume precisely equal stations from oneanother and from the zero reference pin 60 previously discussed. Theyare held from turning out of their adjusted position by an individualset screw or by jam nuts, not shown. A V-notched locking pawl 118 isslidably carried bythe carriage base 108 for engaging a selected pin'60.The pawl 118 is operated by a cam bar 120 which is carried by the pawl118 and which is engaged by a locking spring 122, so as to affordlocking as will now be explained.

In FIGURES 7 and 8, the cam bar 120 is engaged by the cam and shaftstructure 62 of preceding FIGURE 3 so asto move between the solid lineposition and the dotted line position 120a, thus imparting correspondingmovement to the pawl 118 to release it from one pin '60 so as to relockit to another. A fixed guide 124 carried by the carriage base 168 at oneside of the pawl 118 cooperates with an oppositely disposed, springbiased guide 126 to keep the position of the pawl 118 aligned inengaging a pin 68 so as to insure absolute centering of the micrometercarriage in a position opposite thereto.

The following description of end truck 34 in FIGURES 9, 10 and 11 is,with the exceptions immediately pointed out, equally applicable to theopposite end truck 32 on the bridge and in the interest of brevity adescription of the latter is omitted. Said truck 34 .carries a set ofhorizontally disposed rollers 128 in tandem relationship confronting theadjacent longitudinal way. In the case of the right way 30 only, one ormore additional spring biased rollers 130 disposed in the horizontalplane are carried by the adjacent truck of the bridge 22 so as to keepthe bridge at its opposite end or more particularly the rollers 128carried by the opposite truck 32 in running contact with the oppositeway 28. The spring pressure on each roller 130 is preloaded by means ofa bolt 132 (FIGURE 11).

In FIGURES 12, 13 and 14, the locator pins 48 carried by eachlongitudinal way have an eccentric portion 7 which is engageable by aV-notched locking pawl 134 and which provides accurate center-to-centeradjustability in the same manner as the locator pins 60 described inconnection with FIGURE 5 preceding. The descri tion of the V-notchedpawl 134 adjacent the end truck 34 of the bridge is applicable to theopposite end truck 32 and in the interest of brevity the description ofthe latter is omitted. A box 136 carried in depending relation by thechannel of the bridge 22 supports a pair of upwardly biasing springs 138which urge the pawl 134 into locked position wedged against a selectedpin 48. A fixed guide 148 is carried by the box 136 at one side of thepawl 134 and cooperates with a spring biased guide 142 at the oppositeside of the pawl 134 to keep the pawl accurately centered and free fromplay.

The crank shaft 52 is journalled at each of its opposite ends in an endbearing 144 and adjacent each of the end bearings the shaft 52 carries acrank 146. The crank 146 engages a cam follower 148 projecting from thepawl 134 in a manner where rotation of the crank shaft 52 in one waycauses the pawl 134 to unlock and in the other way causes the pawl '134to relock within the box 136.

In the operation of the device of the preceding figures, let it beassumed that the micrometers 68 and 70 are in their fully retracted, orzero, positions. The operator twists one of the handles 54 or 56 tounlock the bridge 22 and he then moves it and relocks it in the locationat which the instrument within the holder 26 approaches the ordinate ofthe desired point on the table 24 to within the nearest inch. Theoperator then twists the handle 64 and moves and relocks the carriage sothat the instrument is slightly to the left of and within an inch of theabscissa of the desired point. Thus he establishes the position of theinstrument both at some whole number of inches past the zero pin 48 and;along the x axis which is transverse thereto, at some whole number ofinches past the zero pin indicated at 60 The operator then rotates themicrometers 68 and 70 one at a time, so as to zero-in the instrument onthe on the table base plate 24. The decimal reading of the micrometer 68is added to the whole number of inches corresponding to the pin 48 towhich the bridge 22 is locked and thus the longitudinal ordinate of thepoint is established. The decimal reading of the transverse micrometer'70 is added to the whole number of inches of the corresponding lockedpin 60 and yields the abscissa, thus completing the fixed coordinates ofthe point. It will be apparent that, if the full travel of eithermicrometer 68 or 70 has failed to bring the instrument into coincidencewith the desired point, the bridge 22 and/or the carriage 20 must besuitably advanced by one pins distance in order to aggregate theappropriate whole number and decimal reading necessary.

Following each punch marking (if doing layout work) or following eachreading (if doing coordinate Work) the operator unlocks the bridge 22and the carriage 20 whereupon the operation is repeated for the nextpoint.

As herein disclosed, the micrometer gages 68 and 70 embodied in theinvention are actually commercially procured micrometers from which theanvil and anvil jaw were removed so that the micrometer can bephysically secured adjacent the slide which it controls. Spot weldingwas the means of afiixation employed and the mircometers read to thenearest 0.001 inch; it is evident that micrometer gages can bemanufactured specially for the present purpose if desired and speciallyadapted so that they can be installed without further modification; itis further evident that accuracy to the nearest ten thousandth of aninch can be achieved with commercially 7 44- and 46 (FIGURE 1) thechance is obviated of having the bridge 22 take a diagonal position andinstead will always be square with respect to the two longitudinal ways28 and 30. Similarly the close proximity of the opposed rollers 110 ofFIGURE 5 obviate the possibility of the carriage 20 taking a diagonalposition and instead it is at all times square to the bridge 22.

Viariations within the spirit and scope of the invention described areequally comprehended by the foregoing description.

I claim:

1. In apparatus of the character described having a lockable carriagestructure and a lockable supporting bridge therefor, said carriagestructure mounted on said bridge for independent movement between lockedposlt-ions thereon along one of two coordinate axes, said bridge mountedfor movement between locked positions along the other coordinate axis,the combination of means for adjusting an instrument with respect tosaid carriage structure, comprising a pair of cooperating slidestructures disposed one on another for establishing limited movement oftravel each at right angles to the sliding movement of the other,individual screw micrometer means supported by said carriage and slidestructures to make screw adjustments to the lides between points oftheir limited travel with respect to said carriage structure, one ofsaid slide structures provided with first means of attachment thereonfor holding said instrument, the other of said slides provided withmeans of attachment to said carriage structure for the limited travelaforesaid, said first means of attachment being offset with respect tothe balance point of said one slide structure, and means freely pivotedto said one slide structure for countering the weight of said instrumentand having separate means of attachment to the latter.

2. In apparatus comprising a pair of mutually perpendicularly disposedprecision devices for holding an instrument of the character described,said devices capable of limited movement of travel each at right anglesto the movement of the other: structures forming movable means formoving the pair of said devices through large increments of displacementalong two axes, and comprising carriage structure for the devices andmovable in a direction along one of the two axes, a fixed base plate,

a bridge structure supported by said base plate for a second directionof movement along the other axis and supporting said carriage structurefor independent movement of the latter in the first-named direction,gage pins fixed along the respective paths of movement of saidstructures at intervals which occur efiectively at equal linear unitsapart, and locking means carried by said structures for locking same tothe appropriate gage pins at points in their paths each corresponding toa selected multiple of said equal linear gage units, the locking meanson said bridge structure comprising a manual operator disposedthereonintermediate its ends, longitudinally disposed shaft means journalled to said bridge structure and extending in opposite directionsfrom said man- 6 ual operator, there being two rows of said fixed gagepins disposed in the path of said bridge structure one at each end ofthe bridge structure, and pawls opera tively disposed one at each outerend of saidshafit means and each engageable and disengageable with gagepins in the row at that end, said shaft means connecting said manualoperator in common to said pawls for controlling their operativeengagement and disengagement aforesaid in unison.

3. In apparatusof the character described having a lockable carriagestructure and a lockable supporting bridge therefor, said supportingbridge mounted for movement between locked positions along one of twocoordinate axes: the combination, with said carriage structure, saidcarriage structure being mounted on said, bridge for independentmovement between locked positions thereon along the other coordinateaxis, of means for adjusting an instrument with respect to said carriagestructure comprising a pair of cooperating slide structures disposed oneon the other for establishing limited movementof travel each at rightangles to the sliding movement of the other, and loading springs andcorresponding screw micrometer means supported by said carriage andslide structures to control movement of adjustment of the respectiveslides between points of their limited travel with respect to saidcarriage structure, one of said slide structures provided with firstmeans of attachment thereon for holding said instrument and being inmutual longitudinal alignment with and separately connected to at leastone loading spring and a corresponding screw micrometer .means, and theother of said slides provided with means of attachment to said carriagestructure for the limited travel aforesaid, and being in mutuallongitudinal alignment with and separately connected to at least oneloading spring and a corresponding screw micrometer means.

4. In combination, a holder for an instrument of the class described, afixed base plate, means for supporting the holder for point-to-pointmovement with respect to said base plate comprising a carriage base, atraversing bridge supporting the carriage base for movement on X ways,and guided thereby with respect to a row of points on said bridgeconforming to an axis of travel parallel to the X direction, said bridgebeing supported for movement on said base plate by Y ways, and guidedthereby with respect to spaced apart rows of points on said base plate,each of the latter said rows conforming to an axis of travel parallel toone another and to the Y direction, a locking pin disposed at each ofsaid points and being eccentrically mounted for precise adjustment inefiectively equidistantly spaced relationship to the other pins in therow, said carriage base carrying a captive V-notched pawl selectivelyoperatively engageable with the pins for locking said carriage base ateach point to the pin at that point on the traversing bridge, andmounting means on said carriage base mounting said holder so as torender it capable of universal rectilinear movement along X and Ycoordinates withrespect to said carriage base.

5. In'combination, a holder for an instrument of the class described, afixed base plate, means for supporting the holder for point-to-pointmovement with respect to said base plate comprising a carriage base,mounting means on said base plate mounting said carriage base thereonfor universal rectilinear movement along the X and Y coordinates, andcomprising a traversing bridge on which the carriage base is guided byand moves on X ways with respect to the traversing bridge, locking meansbetween said bridge and carriage base comprising an extended series offixed locator pins on said bridge defining a row of points parallel tothe X ways and secured to the bridge by eccentric connections afiordingeffective, equidistantly spaced apart locations of the fixed pins, saidcarriage base carrying a captive vV-notched pawl selectively engageablewith the fixed pins for locking the carriage base at each point to thepin at that point on said bridge, said second mounting means on saidcarriage base mounting said holder so as to be capable of independent,limited universal rectilinear movement along "the X and Y coordinateswith respect to said-carriage base.

6. In combination, a holder for an instrument of the class described,a'fixed base plate, means for supporting the holder for point-to-pointmovement with respect to said base plate comprising a carriage base,mounting means on said base plate mounting said carriage base thereonfor universal rectilinear movement along the X and Y coordinates, secondmounting means on said carriage base mounting said holder so as to becapable of limited universal rectilinear movement along the X and Ycoordinates with respect to said carriage base, the first named mountingmeans including a traversing bridge and equidistantly spaced apart,fixed gage pinsand being capable of point-to-point positioning on bothcoordinates to a multiple of a unit of coordinate distance, there being,on the traversing bridge, a first row of said gage pins parallel to theX direction, there being, on the fixed base plate, a second row of gagepins parallel to the Y direction, .a gage-pin contacting pawl shiftablycarried by the carriage base and interengageable selectively with thegage pins of the'first row, and a gage-pin contacting pawl shiftablycarried by the bridge and interengageable selectively with the gage pinsof the second row, said second mounting means including gage elementsand being capabio of point-to-point positioning on each of thecoordinates to a decimal submultiple not exceeding said unit.

7. In combination, a holder for an instrument of the class described, afixed base plate, means for supporting the holder for point-to-pointmovement with respect to said base plate comprising a carriage base, aprimary coordinate system comprising mounting means on said base platemounting said carriage base thereon, a secondary coordinate systemcomprising mounting means on said carriage base mounting said holderwith respect to said carriage base, the first-named mounting meansincluding relatively large increment gage elements and arranged forinsuring point-to-point positioning on each of the X and Y coordinatesto a multiple of a whole unit of coordinate distance, said mountingmeans of the secondary coordinate system including relatively smallincrement gage elements and being capable of point-to-point positioningon the X and Y coordinates to a decimal submultiple of said whole unit,manually operated locking pawls which are elfec-tive to control thefirst named mounting means along the respective X and Y coordinates andcomprising at least two pawls operated by a common actuator and carriedby the first mounting means to interengage with selected ones of thelarge increment gage elements, said large increment gage elementsconsisting of pin means which are provided in rows and at least two rowsof which are on said fixed base plate and fixed in parallel relation tothe Y direction for engagement by said two pawls, and a pair of manuallyoperated devices which are connected to the small increment gageelements and different ones of which are effective to control thesecondary system along the respective X and Y coordinates.

8. In combination, a fixed base plate, a carriage base, a bridgesupported on the fixed base plate and guided by Y ways thereon, andsupporting the carriage base, a row of fixed gage pins adjacent each endof the bridge, and fixed to the base plate adjacent that end of thebridge and in close relation to and parallel with an adjacent Y way,remotely controlled pawls, shiftably carried by the bridge at itsopposite ends and each engageable with a corresponding selected pin inthe row at that end for locking the bridge, a slide member arrangement,and mounting means on said carriage base mounting said slide memberarrangement on the bridge so as to be capable of universal rectilinearmovement along X and Y coordinates with respect to the bridge and fixedbase plate, said mounting means including a pair of micrometer gageelements each of which is eiiective to gage a position along a difierentcoordinate from the other micrometer gage element, said slide memberarrangement being formed of mutually-perpendicularly arranged slidemembers consisting of an instrument holder member and a cooperatingslide member and each in axial alignment with and engaged by a difierentmicrometer gage element for accurately establishing the longitudinalposition taken by each slide member within the travel of its respectivemicrometer gage .element, said pair of micrometer gage elements beingcarried one on said carriage base and one on the aforesaid cooperatingslide member for jointly establishing the final position of theinstrument holder member.

9. Layout apparatus, including primary and secondary coordinate systemsfor accurately establishing X'and Y coordinates in positioning aninstrument of the class described, said apparatus comprising a baseplate, a pair of cooperating slides in the secondary coordinate systemdisposed one on the other for establishing limited movement of travel,each at right angles to the sliding movement of the other, the primarycoordinate system of said apparatus comprising a carriage for carryingsaid pair of slides rectilinearly in the X direction, a bridgesupporting said carriage on carriage-guiding X ways and supported on YWays on said base plate for guided rectilinear movement, locking meansfor locking said bridge to said base plate and said carriage to saidbridge, each incident to making point-to-point movement corresponding tosome multiple of a linear unit, said locking means comprisingindividually cngageable locator pins corresponding to each of the pointsaforesaid, and disposed in two rows on said base plate parallel to the Ydirection and in a third row on said bridge parallel to the X direction,pawls carried by the bridge and by the carriage, manually operated meanson said carriage connected to the pawl thereon for controlling same inpositions of interengagement with selected locator pins in said thirdrow, and individual micrometer means for adjusting said slides betweenpoints of their limited travel, each to a decimal submultiple ofisaidlinear unit, the upper one of said slides provided with means thereonfor holding said instrument.

10. Apparatus of the character described having a lockable carriagestructure and a lockable supporting bridge therefor, said carriagestructure being mounted on X Ways on said bridge for independent, guidedmovement between locked positions thereon, said supporting bridge beingmounted on Y Ways for guided movement between locked positions in the Ydirection, a row of locator pins on said bridge disposed parallel to theX direction and each pin corresponding to one of said locked positions,a notched pawl carried by said lockable carriage structure andinterengageable with a selected pin in each position of the carriagestructure, means for adjusting an instrument with respect to saidcarriage structure comprising a pair of cooperating slide structuresdisposed one on the other for establishing limited movement of travel,each at right angles to the sliding movement of the other,

-and individual screw micrometer means supported by said carriage andslide structures to make screw adjustments to the respective slidestructures between points of their travel with respect to said carriagestructureyone of said slide structures provided with first means ofattachment capable of limited movement of travel each in a diiferent oneof the X and Y directions from the other: the combination of moveablestructures for moving the pair of said devices through large incrementsof displacement in said directions, said structures including a carriagestructure for the devices and having X ways therebeneath, a fixed baseplate, a bridge structure supported on Y ways by said base plate so asto be constrained in guided movement thereon, said bridge structuresupporting the X ways beneath said carriage structure so that the lat erhas independent, constrained, guided movement relative to the bridgestructure, gage pins fixed along the respective paths of movement ofsaid structures at points which occur effectively at equal linear unitsapart, said fixed base plate carrying at least two rows of said gagepins and said bridge structure carrying at least one row of said gagepins, and notched pawls mounted to and permanently carried by saidstructures for locking each to the appropriate gage pins and beinginterengageable with selected gage pins at all points in their paths,each of said gage pins having a position in its row corresponding to aselected multiple of said equal linear gage units.

12. In apparatus comprising a pair of mutually perpendicularly disposedprecision devices for holding an instrument of the character described,said devices capable of limited movement of travel each in a difierentone of the X and Y directions to the other: the combination ofstructures constituting moveable means for moving the pair of devicesthrough large increments of displacement in X and Y directions, saidstructures comprising carriage structure for the devices having X waystherebeneath, a fixed base plate, a bridge structure supported on saidbase plate by Y ways so as to be constrained in guided movement thereon,and supporting the X ways beneath said caniage structure so that thelatter has independent,

constrained guided movement relative to the bridge structure, gage pinsfixed along the respective paths of movement of said structures atpoints which occur at linearly equidistant units apart, said gage pinseach having an engageable portion and a mounting portion which aremutually eccentric to one another, means formed on a portion of each pinfor rotating it to change the position of its engageable portionrelative to a companion gage pin and thus efiectively establish the pinpositions so as to maintain them at said linearly equidistant unitsapart, and shiftable pawls mounted to and permanently carried by saidstructures for locking same and appropriately engageable with selectedgage pins at the points in their paths, each successive gage pin havinga position corresponding to a selected multiple of said linearlyequidistant gage unit.

References Cited by the Examiner UNITED STATES PATENTS 1,003,766 9/11Little 33-79 1,262,015 4/ 18 Carlson 33-80 1,665,842 4/28 Brunings33-1845 1,668,592 5/28 Huebner 33-1845 1,977,213 10/34 Slobey 33-802,198,757 4/40 Bohrn et a1. 33-1 2,298,875 10/42 DOWell 33-174 2,305,16712/42 Kasper 33-23 2,397,109 3/46 Hedin 33-26 2,445,533 7/48 Mondron eta1 33-80 2,565,608 8/51 Hoff. 2,812,580 11/57 Masinda 33-125 2,879,5993/59 Masinda 33-125 2,889,757 6/59 Oole 33-174 2,941,303 6/60Middlestadt 33-174 2,999,317 9/61 Alderson 33-26 FOREIGN PATENTS 541,88012/41 Great Britain.

ISAAC LISANN, Primary Examiner.

12. IN APPARATUS COMPRISING A PAIR OF MUTUALLY PERPENDICULARLY DISPOSEDPRECISION DEVICES FOR HOLDING AN INSTRUMENT OF THE CHARACTER DESCRIBED,SAID DEVICES CAPABLE OF LIMITED MOVEMENT OF TRAVEL EACH IN A DIFFERENTONE OF THE X AND Y DIRECTIONS TO THE OTHER: THE COMBINATION OFSTRUCTURES CONSTITUTING MOVEABLE MEANS FOR MOVING THE PAIR OF DEVICESTHROUGH LARGE INCREMENTS OF DISPLACEMENT IN X AND Y DIRECTIONS, SAIDSTRUCTURES COMPRISING CARRIAGE STRUCTURE FOR THE DEVICES HAVING X WAYSTHEREBENEATH, A FIXED BASE PLATE, A BRIDGE STRUCTURE SUPPORTED ON SAIDBASE PLATE BY Y WAYS SO AS TO BE CONSTRAINED IN GUIDED MOVEMENT THEREON,AND SUPPORTING THE X WAYS BENEATH SAID CARRIAGE STRUCTURE SO THAT THELATTER HAS INDEPENDENT, CONSTRAINED GUIDED MOVEMENT RELATIVE TO THEBRIDGE STRUCTURE, GAGE PINS FIXED ALONG THE RESPECTIVE PATHS OF MOVEMENTOF SAID STRUCTURES AT POINTS WHICH OCCUR AT LINEARLY EQUIDISTANT UNITSPART, SAID GAGE PINS EACH HAVING AN ENGAGEABLE PORTION AND A MOUNTINGPORTION WHICH ARE MUTUALLY ECCENTRIC TO ONE ANOTHER, MEANS FORMED ON APORTION OF EACH PIN FOR ROTATING IT TO CHANGE THE POSITION OF ITSENGAGEABLE PORTION RELATIVE TO A COMPANION GAGE PIN